First-principles study of lattice dynamical and thermodynamic properties of Li<sub>2</sub>NH

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Abstract

One of the key issues for scale applications of hydrogen energy is the availability of safe, efficient and ecnomicical hydrogen storage technologies. In the past few years, light metal hydrides have attracted considerable attention due to their high hydrogen capacity. With a hydrogen capacity up to ~6.5 wt%, Li ₂NH is regarded as one of the most promising hydrogen storage materials. Although the hydrogen physical and thermodynamic properties of Li ₂NH have been studied, the electronic structure, phonon vibration mode and thermodynamic properties of Li ₂NH have not yet been resolved. In this paper, by using the first principles based on the density functional theory (DFT), we investigate the electronic structure, lattice dynamical and thermodynamic properties of Li ₂NH in detail. Firstly, the structure of Li ₂NH is optimized and the lattice parameters and total energy of the crystals are calculated. As shown by the calculation results, the lattice parameters are in good agreement with previous theoretical and experimental results. Our lowest-energy structure of Li ₂NH has orthorhombic Pnmasymmetry at T=0 K for all of the proposed structures. Secondly, the electronic band-structure studies reveal that Li ₂NH has a small band gap of about 2.0 eV. The analysis of total and partial density of states of Li ₂NH show that the bonding between the N and H has a covalent character. Thirdly, the lattice dynamical properties of Li ₂NH are investgated at the corresponding equilibrium states. These results show that only the phonon dispersion curves of Li ₂NH ( Pnma) without negative frequencies are calculated along the high-symmetry points. The optical modes of phonon frequencies at Γpoint are assigned as Raman and Infrared-active modes. Based on the calculated phonon density of states, the thermodynamic properties are computed, such as the Helmholtz free energy, internal energy, entropy and the constant-volume specific heat versus temperature. The calculation results may explore the applications in areas of hydrogen storage for Li-N-H, which is of great importance forusing hydrogen in the future.

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Corresponding author:Ma Jun-Gang,jgma@bjtuhbxy.cn

Funds:Project supported by the Emergency Management Program of the National Natural Science Foundation of China(Special Funds for Theoretical Physics)(Grant No. 11547224) and the Research and Practice of the Higher Education reform in Hebei Province, China (Grant No. 2018GJJG649).

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[7]
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[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]

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Space group	Lattice parameter/Å			E_tot/eV
	Present	Experimental	Other Calculated	Present
$F\bar 43m$	a= 5.6249	a= 5.0769^[2]	a= 5.159^[17],5.223^[17],5.074^[17],5.649^[16],5.1076^[18],5.2968^[9]	–1920.4448
$Pnma$	a= 7.781 b= 3.623 c= 4.902		a= 7.733^[8],7.704^[16],7.742^[17],7.753^[17],7.775^[17] b= 3.60^[8],3.75^[16],3.604^[17],3.609^[17],3.618^[17] c= 4.872^[8],5.074^[16],4.883^[17],4.890^[17],4.881^[17]	–2702.3588
$Fm\bar 3m$	a= 5.0696	a= 5.0742^[3]	a= 5.047^[3],5.045^[16]	–1913.6655

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B_2u	B_1u	B_3g	B_2g	B_3u	A_u	B_1g	A_g
123.6	137.9	160	161.5	168	198.5	222	223.5
310	195.8	380	232.0	289	243.0	359	287
408	318	432	300	350.5	446	435	335
644	450	660	350.5	385	625	654	380
	550		412	620			542
	630		580	668			598
	3122		640	3123			3132
			3134

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Temprature/K	S/J·(mol-c·K)^–1	C_V/J·(mol-c·K)^–1	ΔH(H–H₂₉₈)/KJ·mol^–1
298	248.9	273.8	0
300	250.2	274.9	2.9
500	405.4	327.1	55.1
700	519.0	347.0	75.0
900	607.7	358.5	86.5
1100	680.5	366.6	94.2
1300	742.3	372.8	100.8
1500	796.0	377.5	105.5

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[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
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Vol. 68, Issue 13 - 2019-07-05

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